Many reaction processes exhibit fouling characteristics. Examples of such reaction processes are conventional polymerisation processes, including the oligomerisation, e.g. tetramerisation or trimerisation of olefins such as ethylene and/or propylene. The fouling of a reactor used in polymerisation reactions is manifested in the building up of a polymer film on an interior surface of a reactor wall and/or on other exposed metal surfaces such as injectors, nozzles, reactor internals and the like. This problem is particularly severe when the surfaces being fouled are at a temperature below the melting point of the polymer. The Applicant has found that this problem is also particularly prevalent on the ethylene injector nozzle and bottom dish of a reactor in which ethylene is tetramerised, with a mound of polymer building up on the bottom dish of the reactor.
A process for polymerising or oligomerising a hydrocarbon and a hydrocarbon polymerisation or oligomerisation reactor, which are less prone to fouling problems and improve heat removal, will be advantageous.